<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS_选择器的优先级</title>
    <style>
        /*优先级代表是优先级高的替换优先级低相同的修饰效果
            优先级顺序：标签选择器<类选择器<id选择器<行内修饰
        */
        h1{background-color: black;color: red}
        .h1{background-color: gray}
        #h1{background-color: aqua}
    </style>
</head>
<body>
<h1 class="h1" id="h1" style="background-color: blueviolet">这是一个表题</h1>
</body>
</html>